Obsessive-Compulsive Disorder (OCD) is a common and severe psychiatric condition, which affects 2-3% of the population and is characterized by anxiety-producing intrusive thoughts and performance of anxiety-reducing rituals. Several studies suggest a genetic component in the etiology of OCD, but unlike schizophrenia and bipolar illness, no genome-wide search for genes has yet been reported for this disorder. Very little is known about the pathogenesis of the disorder.
Numerous early studies involving the serotonin-specific reuptake inhibitor clomipramine led to the hypothesis that OCD may be associated with dysregulation of serotonergic neurotransmission. Indeed, serotonin reuptake inhibitors have been established as the first-line pharmacotherapy of OCD. However, approximately one-half of the patients who receive an adequate trial with these agents remain clinically unchanged. Use of dopamine antagonists to augment treatment of patients resistant to serotonin uptake inhibitors appears to be a useful approach for a subset of OCD patients, thus implicating involvement of dopaminergic pathways. However, there has heretofore been no method available to screen patients to ascertain the appropriate course of therapy. Often, it can take weeks, or even months, to establish the inappropriateness of the therapy, resulting in a continuance or worsening of the patient's condition.
Therefore, in view of the aforementioned deficiencies attendant with prior art methods of diagnosing and treating obsessive-compulsive disorder, it should be apparent that there still exists a need in the art for a method which can reliably distinguish between the populations for which therapy with dopamine antagonists is appropriate, so that early treatment can be initiated.